[Rutger Gert-jan]

Hi,



Today I experienced a heavy virbration while pulling away at a traffic light. It only happens in 1st gear. My question is could it be the clutch or is it the DMF? The clutch already behaved a bit funny for a month now, so I already ordered a new clutch set from Sachs. I will also order al the parts operating the clutch (fork bearings, slave cylinder etc.) I also spoke to a guy from an OPC, he suggested that maybe one of "the fingers" from the pressure plate might have come of....So am I in for a new DMF as well? Or could it be bad motor mounts?, I think it is a good idea to replace them as well ( a sort of while you are in there... <img src="/forum/images/smilies/968/wink.gif" class="smilie" alt="" /> )



Looking forward to your findings,





Regards,



Rutger

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[94SilverCab]

DMF will generally cause vibration through the shifter at all speeds. While that may be a part of your problem I think you should consider the possibility that it is motor mounts.



JMHO



Jay

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[unknown4u]

I'll keep it at the motor mounts.

The same description you gave had a friend of mine with his 928.

After changing the mounts the problem was over.



Ritchie.

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[SILVY968]

[quote name='Rutger' post='44798' date='Dec 19 2007, 09:42 AM']Hi,



Today I experienced a heavy virbration while pulling away at a traffic light. It only happens in 1st gear. My question is could it be the clutch or is it the DMF? The clutch already behaved a bit funny for a month now, so I already ordered a new clutch set from Sachs. I will also order al the parts operating the clutch (fork bearings, slave cylinder etc.) I also spoke to a guy from an OPC, he suggested that maybe one of "the fingers" from the pressure plate might have come of....So am I in for a new DMF as well? Or could it be bad motor mounts?, I think it is a good idea to replace them as well ( a sort of while you are in there... <img src="/forum/images/smilies/968/wink.gif" class="smilie" alt="" /> )



Looking forward to your findings,

Regards,



Rutger[/quote]



I had the same problem. It was the pressure plate. I would think that a DMF problem would express itself all of the time.

Brian

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[Cloud9...68]

Bad motor mounts tend to produce the most noticeable vibration at idle. One of mine was split before I replaced it, and my car didn't exhibit the vibration when pulling away in first gear as you describe. I vote for something clutch related.

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[Scott Collins]

Hello Rutger,



If you have one bad mount, the headlight on that side will vibrate much more than the other, which

should stay virtually still at idle. This, along with a visual inspection of the mounts will tell you if

one or both mounts are bad.



Last time I replaced mounts was on my '87 944, and it was one of the easier jobs I have done.



Best of luck.



Scott

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[SILVY968]

Rutger,



Have the PM check the DM flywheel for correct rebound. Mine was shot which contributed to the problems. It felt like I had lost my ability to smoothly move from a stop. The pressure plate problem vibrated my car at all speeds, so I think the flywheel is more likely; a more expensive problem to fix, but it does give you the option of going with a new lightweight flywheel from Pete at RS Barn.

Brian

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[Cloud9...68]

[quote name='Scott Collins' post='44815' date='Dec 19 2007, 08:58 PM']Last time I replaced mounts was on my '87 944, and it was one of the easier jobs I have done.[/quote]



Yikes! I don't know about the 944, but on the 968, I found changing the engine mounts to be a royal pain. There's quite a bit of dissassembly involved, including removal of the cross-member, which legend has it necessitates an alignment afterwards (though some have disputed this). I needed one anyway, so I did it. Compared to the mounts, replacing the clutch master/slave cylinder, and installing the steel braided line, was a walk in the park!



Unfortunately, I've heard that replacing the flywheel is also quite the task (though apparently just replacing the clutch is relatively easy). Good luck!

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[Rutger Gert-jan]

Hi guys,



thankx for all the input. I will bite the bullet and replace the motor mounts as well. I do have one question, how can I see that my flywheel is still in good order?(apart from scratches/ binding marks etc.) or should I just replace the clutch disk and see what happens?



Regards,



Rutger

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[SILVY968]

Rutger,



When I had the problem my PM was able to drive it and he could tell that it was the flywheel. He said that if I wanted to invest the time, as there was some taking apart to do, that there was a "rebound" test that would determine if the flywheel was in spec. I have never seen this test or spec in print, but I trust my PM and when we pulled the clutch and flywheel out, the flywheel was indeed bad. When it was replaced it was as smooth as a new car and was a pleasure to drive!

Brian

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[MATTS92]

[quote name='Rutger' post='44798' date='Dec 19 2007, 12:42 PM']Hi,



Today I experienced a heavy virbration while pulling away at a traffic light. It only happens in 1st gear. My question is could it be the clutch or is it the DMF? The clutch already behaved a bit funny for a month now, so I already ordered a new clutch set from Sachs. I will also order al the parts operating the clutch (fork bearings, slave cylinder etc.) I also spoke to a guy from an OPC, he suggested that maybe one of "the fingers" from the pressure plate might have come of....So am I in for a new DMF as well? Or could it be bad motor mounts?, I think it is a good idea to replace them as well ( a sort of while you are in there... <img src="/forum/images/smilies/968/wink.gif" class="smilie" alt="" /> )



Looking forward to your findings,

Regards,



Rutger[/quote]

I dont know if its the same problem i had . I had trouble pulling away in first, only the ca r would buck just a bit.It went away after i installed a new master cyl, hose and slave. Hope this helps.

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[Rutger Gert-jan]

Again thanks for this suggestion, I will replace the cylinders first and see if it makes any difference. I will replace the motor mounts if this does not help and last but not least the clutch ass.



Regards,



Rutger

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[Cloud9...68]

If you do the mounts, let me know, and I can send you the instructions I followed. One thing I tried to do, but wouldn't do again, is move the crossmember as little as possible, in hopes of changing the alignment as little as possible (in case I changed my mind about the alignment). If I had to do it again, I would completely remove the cross-member, which would have made it much easier to maneuver the engine back onto the mounts. With the approach I used, it took a neighbor and I a good two hours to get things to line up well enough to allow the engine to seat properly. As I said, it was a massive pain. I'll have to check the instructions to see if I'm remembering this right, but I remember pretty clearly thinking how much easier it would have been to have the extra degree of freedom of having the cross-member completely removed.



And I agree that my clutch feel improved significantly after I replaced the master & slave cylinder, and the high pressure line. I didn't have the vibration problem you're experiencing, so I can't say whether replacing these parts would have helped with this, but it can't hurt to try. Neither the clutch M & S & line replacement, nor the engine mount replacement, are exactly trivial jobs, but I wasn't kidding when I said the clutch cylinder replacement was MUCH easier than the motor mount job. The former just requires a little patience, and moving all the lines and hoses out of the way before you start.

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[jaap]

Hi Rutger,



I still wonder what kind of vibration you have. Is this what is known as clutch 'judder' which makes you feel you don't know how to operate a manual and seems to happen to many 968's while stuck in traffic. This is what my car also had but would go away when everything cooled down again. This could also be a sign of oil or grease on the clutch plate which in the end forced me to replace the clutch and also solved this kind of vibration/judder when hot.



Jaap

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[Rutger Gert-jan]

Hi everybody,





At the moment I am still waiting for the parts to arrive (clutch fork, bearings etc and the cylinders+motor mounts. All ordered at Paragon Products) I think these parts will arrive after X-mas. As soon I start replacing parts I will let you know what was wrong.





Best Wishes for Christmas and the new year!



Rutger

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[Cloud9...68]

Did you also order the steel braided high pressure clutch line from RS Barn? You definitely don't want to go to the trouble of replacing the master and slave cylinder, and put back the old line, as these things are a known weak spot on the 968, and quite a few have blown over the last couple of years.



Come to think of it, on rare occasions, my car also does judder a bit when pulling away in first gear. I always assumed it was just the nature of the car. Hmm... I'll have to keep an eye on it to see if it gets worse. Could be an excuse to go for Flash's new spring-centered clutch disk with an aluminum flywheel...

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[doors1024]

....heavy virbration as in it feels like its going to stall out???

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